Question

Two chips are being considered for use in a system. Lifetime of
chip 1 is modeled by a Gaussian RV with mean 20,000 hours and
standard deviation 4000 hours. (Probability of negative lifetime is
negligible) Lifetime of chip 2 is also a Gaussian RV with mean
22,000 and standard deviation 1000 hours. Which is preferred if the
target lifetime of the system is (i) 20,000 hours and (ii) 24,000
hours?